Now that the economy has started to pick up, growing companies may need to consider their options if they’ve started to outgrow their current facilities. Regardless of whether or not the original building is a metal building, a pre-engineered metal building can be a cost-effective and quick solution to a company’s needs.
Initial Considerations
As with any project, there are a number of things that need to be considered before starting an addition to an existing building. The first is the condition of the existing building and whether or not it can handle an addition. The condition of the existing building is important whether an owner plans on adding width or length to the building, and especially if the owner plans on adding a second story. If the existing building is not in a suitable condition, the owner may be better off demolishing it and starting over.
If the existing building is in good condition, the owner may still need to update the building to remain in accordance with current building codes. If the existing building is older, the building and energy codes have likely changed, and depending on the scope of the project, it may need to be brought up to current codes. Site conditions also need to be considered, such as whether the new structure can be accommodated soil wise, and confirming there is enough space to actually build a new addition.
When considering an addition to any building, Wilbur Ferland, LEED AP, building consultant at Sheridan Construction Corp., Fairfield, Maine, says ideally the site development should be conducive for future additions. “Consideration to grades, utilities, both overhead and underground, must be accounted for, no matter what type of structure is selected,” he says. “The site designer must be made aware of future plans.”
And, Ferland goes on to say that in regards to structural requirements, depending on the codes, loads and building usage at the time of construction of the original building, the future addition may or may not be able to utilize the existing building’s fame for support. “If an owner doesn’t have a set plan and timetable for a future addition, it may not make sense to ‘beef’ up the building, since it is unclear if it will meet future requirements,” he adds.
Jim Peckham, manager of marketing at Varco Pruden Buildings, Memphis, Tenn., says owners and contractors also need to understand the type of addition that they’re planning on doing, whether it’s going to be a sidewall, an endwall, or both. “You don’t want to create snow load conditions that could affect your existing structure,” he explains. “You don’t want to run into roof slope issues about managing water drainage from an existing structure. You don’t want to create flashing issues from the old structure to the new structure. There are all big things that you have to look at.”
“When adding an addition that is taller than the existing building you will need to take into consideration that you will be putting an additional snow load on the existing structure that will need to be reinforced,” adds Kim Pesch, district manager at Houston-based Metallic Building Co. “If the existing building is taller than the addition any additional snow load will be on the new addition and will be designed for, so no additional material is needed.”
Aesthetics
Another consideration is how closely the new addition needs to match the aesthetics of the original structure. This includes matching the existing panel types and colors, the roof geometry and slopes, the load conditions and building clearances. “Since there are so many finish options available [with pre-engineered metal buildings], it’s usually not an issue, but it needs to be considered,” says Arthur E. Hance, president of Hance Construction Inc., Washington, N.J.
Pre-engineered metal buildings provide a variety of flexible design options. “Standard bay spacing is around 25 feet but with Metallic Building’s LongBay joist we can do bay spacing up to 65 feet,” Pesch notes. “Also, with pre-engineered buildings the engineering and stamped drawings are provided by us, which usually helps metal building systems provide a quicker lead time, better price and faster installation when compared to conventional construction.
When it comes to deciding the type of metal building that is best for your project, Peckham says that working with the contractor and building manufacturer will help determine the proper building for your budget. “Whether you need an open space versus interior walls may determine which framing or secondary systems will be the most economical for your budget,” he says. “The size of your project may determine the best roof systems to choose. R-panel roofs may be a better option for a smaller span, or a higher pitch roof may be better than a standing seam roof designed to handle lower pitch needs.”
Expanding and Adding On
While building an addition to an existing metal building can be a simpler project, Peckham notes it’s not hard to add a metal building to a conventionally constructed building. In those cases, there can be issues in regards to flashing between the two buildings, differing roof slopes and drainage. “Roof slopes could affect both types of buildings,” he says, “but they predominately become an issue when you’re talking about a non-metal building.”
If you know you’re going to be expanding your building when you’re constructing the original structure, Peckham recommends choosing a full-frame expandable end frame versus a half-load frame or post and beam. “These frames are designed to allow additional bays to be added without reinforcing the end frame,” he explains. “Frames can also be designed for future loads, such as cranes, lean-tos and more.”
Hance recommends that when designing the original building, the design team should make sure that bracing, doors, ground-mounted equipment, etc., will not interfere with future expansion plans. “A metal building can also be configured with an expandable endwall or sidewall columns that can be designed to support a width extension,” he says.
Ferland says the building geometry should consider any future expansion plans. “While initial construction costs may be more, if future expansion is a priority, this may be money well spent,” he says. “For example, if 14-foot clear height is a requirement and the owner plans on a future width extension, do not build a building with a 14-foot clear height unless there are plans for a multiple-width gutter. Listen to an owner’s needs and make recommendations accordingly.”
If an owner has no designs for future expansion, then typically a bearing endwall is used. “If future expansion is needed, we can use an expandable endwall frame, so when it comes time for expansion the contractor can tie in to the expandable endwall with no need for an additional frame,” Pesch adds. “The existing sheathing and girts can remain or be relocated to the end of the new addition depending on the owner’s needs.”
Expandable endwalls make it easier to make an existing building longer. If you want to make the existing building wider, Pesch says if the existing structure is a single-slope building, another duplicate building can be added on to the high side of the building, creating a gable building.
“Even if the existing structure is a non-metal entity, it doesn’t mean that metal couldn’t be the right solution,” Peckham explains. “Even if you want to match a block wall, or a non-metal wall condition, you can still do it with a pre-engineered solution. And most manufacturers understand how to handle flashing issues, making sure that particular attention is paid where the elements join together to ensure the building is watertight for a long, long time.”
“The most common challenge,” Peckham continues, “is when someone thinks [a building] has to be the conventional metal building with metal wall panels. There are many options for the walls of a metal building, from block, brick, precast, horizontal or vertical metal, and more. Materials in metal buildings are not limited to rollformed sheet metal. Beautiful wineries, churches, architect offices, and more can all be designed around metal building systems.”
“We have expanded many buildings, from pre-engineered metal buildings to conventional structures of steel, CMU bearing, wood and even pre-engineered wood structures on occasion,” Ferland says. “Every building and addition is a prototype and has its own challenges. The preferred building to expand is one which the possibility of future expansion was incorporated at time of construction and all as-built information is available.”
